ABSTRACT

The primary symptom of hardlock of cotton is during boll opening the fiber does not fluff out but instead stay in tight wedges, often not extending beyond the boll. Mechanical pickers cannot extract the cotton fiber and the lock itself is often knocked to the ground. Hardlock of cotton is a complex disease that apparently can be induced by several different phenomena. It is associated with stink bug damage, seed rot, and - the emphasis of this paper - the fungus Fusarium verticillioides (formally F. moniliforme). We propose that hardlock of cotton be considered a subset of the more general boll rots, with a major difference in that with hardlock the fiber does not fluff out when the boll opens, but the boll itself is not decayed as in traditional boll rots. At present it is impossible to predict if a boll will fluff out normally before opening. We feel that Fusarium hardlock, as a subset of the hardlock complex, can be controlled with appropriate fungicide applications.